Killed in the March 14, 2011, fire at The Boulders apartments, near 750 South and 650 West in Provo, were Karen Murray and Catherine Crane.
Yvette Kimber who allegedly set the fatal fire has pleaded not guilty in 4th District Court to two counts of murder and one count of aggravated arson, all first-degree felonies.
Kimber, 46, is also charged with one count of second-degree felony aggravated assault resulting in serious bodily injury in connection with Spahr.
Stone, a friend of Murray, was attending Kimber's court hearings when she met Spahr, who suffered burns and broke her pelvis as a result of jumping from the second story of the flame-engulfed building.
Stone said Spahr spent about five months at the University Burn Unit after the fire before moving to the care facility, but had started attending the court proceedings even though she could barely walk and used a walker or wheelchair.
Spahr had seemed to be doing better and was upbeat and happy, Stone said, but she had not showed up for the past few court hearings.
"Even though she was suffering, she was happy, she wasn't mad at Yvette," Stone said, adding that Spahr planned to testify against Kimber in a jury trial scheduled for July.
Provo police Sgt. Brandon Post said an autopsy will help determine if the cause of Spahr's death is in any way connected to the injuries she suffered in the fire.
"We are investigating it to see if it is related," Post said.
Mariane O'Bryant, with the Utah County Attorney's Office, said if prosecutors can show Spahr's death was a result of injuries sustained in the fire, they will amend the aggravated assault charge to a murder charge.
Kimber told police that the night of the fire, she took pills, drank alcohol and smoked marijuana, believing she could fall asleep with a cigarette and start a fire. After she woke up she tried to light paper, her couch and the pillows of her love seat on fire, court documents state.
"We are all going to miss [Spahr]," said Stone, who will now attend the trial on behalf of two deceased friends. "It is just a shock that she made it though the fire, and her dying is another shock."